The LISA Zero-Signal Solution
Classical and Quantum Gravity
We derive a time-delay interferometric (TDI) combination that has zero-response to a gravitational wave signal. This combination, which we have called the zero-signal solution, is a two-parameter family of linear combinations of the generators of the TDI space that has null gravitational wave response when its two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the zero-signal solution does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind.
The LISA zero-signal solution. Massimo Tinto and Shane L. Larson. Classical and Quantum Gravity 22, S531-535 (2005).